// 解析 Symbol 对象

let names ;

console.log( '- - - - - Symbol静态属性 - - - - -' );

names = Object.getOwnPropertyNames( Symbol );
console.log( names );

console.log( '- - - - - Symbol原型属性 - - - - -' );

names = Object.getOwnPropertyNames( Symbol.prototype );
console.log( names );
// console.log( typeof Symbol.prototype[ 'description' ] );

console.log( '- - - - - Symbol"无"构造 - - - - -' );

// Symbol( [ description ] )
let primitive = Symbol('王燕');
console.log( primitive , typeof primitive );

// 借助Object函数将 原始值 包裹到 Symbol类 的一个实例中
let instance = Object( primitive );
console.log( instance , typeof instance );

console.log( primitive == instance );
console.log( primitive === instance );

console.log( instance.description );
